Re: [Dcrup] I-D Action: draft-ietf-dcrup-dkim-usage-02.txt

Scott Kitterman <sklist@kitterman.com> Mon, 12 June 2017 14:57 UTC

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From: Scott Kitterman <sklist@kitterman.com>
To: dcrup@ietf.org
Date: Mon, 12 Jun 2017 10:57:40 -0400
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Subject: Re: [Dcrup] I-D Action: draft-ietf-dcrup-dkim-usage-02.txt
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On Monday, June 12, 2017 03:41:01 PM Martin Thomson wrote:
> On 12 June 2017 at 15:32, Scott Kitterman <sklist@kitterman.com> wrote:
> > The way to do that would be to remove it from the protocol, which you seem
> > to oppose, so I'm confused.
> 
> I don't oppose removing it from the protocol in practice, it's just
> that you can't pretend that the old version doesn't exist, and nor
> should you care.  The point is to not USE it, the definition becomes
> harmless at that point.

I disagree on that point, but I guess we'll see what others think.  I think as 
long as it's in the protocol, it's problematic.

> > 1024 is operationally very common.  In the end, if it matters, I don't
> > mind
> > adding this discussion, but I also don't see any reason to set the floor
> > higher than 1024 (I don't think there's enough security advantage in 1156
> > over 1024 to matter).
> 
> This I agree with.
> 
> The reason I suggested this is that your current draft doesn't
> *actually* include any new advice about key sizes.  1156 would be
> advice you could give, but as I said, that's of marginal benefit.

Yes.  It's focused on trying to define a secure/interoperable set of 
requirements that are common between senders and receivers.  I didn't see 
anything that really needed updating about the drivers for choices within 
those bounds.

Scott k